Windows 7 Media Player problems

I am running windows 7 and I use the windows media player. Just recently, after a restore, I can convert files to mp3 and save them in media player and they play back fine. When I try to burn them, all of the files give an error saying that media player doesn't know what size the files are. I went into control panel and then troubleshooting and it said my media player was corrupt. I deleted every file in my media player and did the media player restore, and it stills says it is corrupt. How do I completely uninstall windows media player and then re-install it. Windows media player is not showing up on the list of programs to uninstall on windows uninstall list, ccleaner uninstall list, or revo uninstaller list. Or is there another solution without using a different player.

Windows Media Player is part of the OS = Operating System, therefore you cannot uninstall it.
I think you need to roll it back to WMP 11 & go from there. Hopefully somebody else in here can help. Good luck.